The present invention relates generally to sterile containers for solutions, being particularly suitable for blood packs within which an autoclaved liquid is stored. This invention encompasses a method and a system or apparatus for preparing sterile containers such as blood bags out of either autoclavable or non-autoclavable materials, as well as the containers made thereby, which containers may be formed of materials that can exhibit superior properties other than those associated with the ability to resist damage under autoclave conditions.
Autoclaved body fluid containers having liquids autoclaved in situ therewithin are well known in the medical equipment art. Representative of this type of flexible packaging are the structures known in Earl U.S. Pat. No. 3,064,647, which specifies that the blood packs described therein are fabricated of plastics such as polyvinyl resins that are able to withstand autoclave conditions, generally understood to include heating in steam and/or hot water baths at a temperature of about 114.degree. C. or more for from about 30 minutes to about one hour. When in use within blood donor systems, this packaging is supplied with a sterile liquid therewithin, usually an anticoagulant. Having a liquid that must be sterile within the package has heretofore dictated the sterilization thereof by a wet sterilization technique compatable with having liquids within the item being sterilized, typically an autoclave process.
Preparing sterile packaging with sterile liquids therewithin heretofore has been carried out by introducing unsterilized liquid into a portion of the container, which liquid will be sterilized together with the container itself, including portions thereof that do not contain the liquid, during subsequent wet sterilization operations carried out within an autoclave apparatus. In such systems it is critical that the material out of which the blood bag or the like is molded will not be damaged, melted, deformed or discolored during the autoclave operation, requiring a plastic having a relatively high melting point, having a relatively high deformation temperature, and otherwise being able to withstand deterioration under autoclave conditions. Even a material such as polyvinyl chloride, in wide use today for such autoclavable packaging, is not entirely satisfactory in this regard because it does tend to exhibit some undesirable changes and can be damaged at optimal autoclave temperatures of 120.degree. C. or higher, often making it necessary to use slightly less than optimum, but still sterilization effective, autoclave temperatures.
Providing blood bags and the like fabricated out of autoclavable materials such as polyvinyl chloride has other potentially undesirable ramifications. Residual plasticizers within certain polymers such as polyvinyl chloride tend to be leached out when blood is stored within such materials for extended time periods. In addition, polyvinyl chloride may not afford optimum storage parameters and does not exhibit the extent of gas permeability that is highly desired for blood packaging.
Certain materials, heretofore unacceptable because of their non-autoclavable properties, are potentially more suitable than autoclavable resins for use as materials for blood bags and the like because they exhibit overall storage parameters superior to those of presently used autoclavable materials such as polyvinyl chloride. Potential leaching problems could also be minimized, if not obviated, by eliminating the need for autoclaving the plastic material itself to significantly reduce the susceptibility of extractables such as residual plasticizers to leach out, which is brought about by subjecting the material to the stress conditions of autoclave operations. Such non-autoclavable materials can also exhibit improved gas permeability properties known to be superior for platelet storage. Certain non-autoclavable materials exhibit increased gas permeability in order to bring about optimum pH adjustments by the passage of gases, especially oxygen and carbon dioxide, through the walls of blood bags made therefrom.
By the present invention, it is possible to use these non-autoclavable materials having such advantageous properties for forming blood bags and the like which must be sterile and which must have a sterile liquid such as an anticoagulant stored therewithin. In an important aspect of this invention, it is possible for the first time to utilize sterilization techniques which heretofore could be put into practice only for preparing sterile products that are essentially completely dry; these dry systems, which are conducted at temperatures significantly lower than autoclave temperatures, include gas sterilization systems and radiation sterilization techniques. In this regard, gas sterilization systems cannot be used to sterilize liquids, and were one to attempt to substitute radiation sterilization techniques for the autoclave techniques used in preparing blood bags having a liquid anticoagulant therein, an undesirable generation of free radicals would result.
These various aspects and advantages of this invention are brought about by a system wherein liquid-containing blood bags or the like, which can be fabricated of non-autoclavable materials such as those mentioned generally for use within dry systems in Walter U.S. Pat. No. 2,702,034, and which can be subjected to dry sterilization conditions to avoid the disadvantages brought about by autoclaving and by using autoclavable materials. Liquid anticoagulant or the like is separately sterilized, typically under autoclave conditions, either in bulk or in premeasured, disposible containers or dispensers. Sterile connector means of the type disclosed in copending Granzow et al., U.S. Ser. No. 843,608, filed in October, 1977, depend from the blood bag or other package and from the dispenser containers to permit sterile transfer of the autoclaved liquid into the previously sterilized unit in order to provide a finished sterile product having autoclaved liquid therewithin, but which finished product itself need not have been subjected to autoclaved conditions.
It is accordingly a general object of the present invention to provide a sterile container that need not have been autoclaved.
Another object of the present invention is an improved system, process, and product produced thereby resulting in a sterile container for body fluids that includes an autoclaved liquid therewithin but which need not itself have been autoclaved.
Another object of this invention is an improved system, process, and product utilizing molding resins that cannot be autoclaved but which may exhibit properties desirable for the storage of body fluids that may not be typically exhibited by autoclavable plastic resins.
Another object of the present invention is an improved system, process, and product which incorporate dry sterilization techniques in conjunction with sterile connectors for sterile transfer of autoclaved liquids into a dry-sterilized container.